Machine for applying powders to printed sheets



Sept. 29, 1959 D. GLADWELL MACHINE FOR APPLYING POWDERS TO PRINTEDSHEETS Fil ed Jan. 3, 1957 4 Sheets-Sheet 1 Attorn v Sept. 29, 1959 a.GLADWELL 2,906,240

MACHINE FOR APPLYING POWDERS TO PRINTED SHEETS- Filed Jan. 3, 1957 4Sheets-Sheet 2 Inventor DA/WEZ 51/40 WFZZ "QQH A Home y Sept. 29, 1959MACHINE FOR APPLYING POWDERS TO PRINTED SHEETS Filed Jan. 3, 1957 4Sheets-Sheet 3 Inventor DA/V/[L amawaz y 9 E 2 6 Attorney D. GLADWE-LL2,906,240

p 1959 D. GLADWELL 2,906,240

MACHINE FOR APPLYING POWDERS TO PRINTED SHEETS Filed Jan. 3, 1957 4Sheets-Sheet 4 Inventor GZADWFZL,

B 9115 B 9 Attorney MACHINE FOR APPLYING POWDERS T PRINTED SHEETS DanielGladwell, Woodford, England, assign'or to The Selwyn Press Limited,London, England Application January 3, 1957, Serial No. 632,282

8 Claims. (Cl. 118-641) This invention relates to a machine by whichpowder is deposited on to the freshly printed surfaces of sheets from apowder container located below the path of travel of the sheets throughthe machine, and is distributed over the surfaces of the sheets,

More especially the invention is concerned with the application offusible, thermo-setting resinous powders to freshly printed sheets toattain relief printing without the aid of costly dies; but it mayinclude the application of other powders, such as bronzing powders andchalk or like powders.

The object of the invention is to provide improved and simplified meansfor picking up the powder from the container and depositing it on to thesheets without the possibility of any of the moving parts of the machinebecoming clogged with the distributed powder and thereby rendering themachine inoperative.-

To the attainment of this object the invention provides a machine forapplying powders to freshly printed sheets, comprising, in combination,conveyor means including a grid afiording an inclined path of travel forthe sheets one following another, a powder container below said grid, amember mounted at one side of said grid for rotation in a substantiallyvertical plane, powder pick-up arms projecting laterally from androtatable with said member in a path circumscribing said grid anddipping into said container, and mechanism for operating said conveyormeans and for rotating said member in timed relationship whereby saidarms pick up predetermined doses of powder from said container anddeposit same successively one dose over each sheet travelling along saidgrid, any unused powder from each dose returning through said grid intosaid container.

Each pick-up arm may be of irregular triangular or polygonal sectionhaving a multiplicity of faces and may be turnably attached at one ofits ends to said rotatable member thus affording a plurality of faceseach of a different total area from the others, any of which faces canbe made to act as the powder pick-up and carrier face of the arm byappropriate setting of the arm, the amount of powder deposited by eacharm being thereby made adjustable.

The sheet conveyor means may include a perforated heated bed as acontinuation of the path afforded by the grid, the sheets being caused,when traveling along this bed, to make intimate contact with the surfaceof the bed by suction effective to remove air between the sheet and thebed. Since air, which is a relatively poor-conducted of heat, isremoved, a more rapid and effective heating (by contact) is attained.Infra-red heating may also be applied to the upper surface of each sheetas it travels over the heated bed.

By way of example an embodiment of the invention, more particularly forapplying powder to printed, letter heading, is illustrated on theaccompanying drawings and will now be described with reference thereto.

Fig. l is a plan of the illustrated machine.

nited States Patent Fig. 2 is a fragmentary elevation of the machine.

Figs. 3, 4 and 5 show details of the powder-applying arrangement, Fig. 3being a plan, Fig. 4 a sectional elevation on line IVIV of Fig. 3, andFig. 5 a front view.

Fig. 6 represents a section on line VI-VI of Fig. 1 of the perforatedheated bed.

As shown by Figs. 1 and 2, the machine comprises a base frame 1 havingtwo laterally spaced upstanding side cheeks 2, a platform 3 at the frontend of the frame for supporting a pile of printed sheets (printed-sidedown) and, between said side cheeks, first a powder-applying zoneaffording a horizontal support 4 followed by an upwardly inclinedsupport 5 for the sheets as they are caused to travel successivelythrough the machine, next a horizontal heated bed 6, and in line withthe latter a cooled bed 7. Co-acting upper and lower endless conveyorbands 8, 10 and rollers 9, 11 suitably driven convey the sheetssuccessively through the machine.

Any appropriate mechanism is provided for transferring the sheetsone ata time from the pile of sheets supported on the platform 3 to thesupport 4. The illustrated mechanism comprises a suction tube 12 havingsuction nozzles 13, this tube being carried by an axle 14 having toothedgears 15 that engage toothed racks 16 on the top of the machine frame 1.The axle v14 is operatively connected by levers 17 and cranks oreccentrics 18 with a shaft 19 which is arranged to be driven, throughbelt and pulley gearing, denoted 20, from a power source such as anelectric motor. When the axle 14, which is both turned and reciprocated,is moved to its extreme forward position over a pile of sheets on theplatform 3 suction is applied, under control of an automatically actingvalve, through the nozzles 13 to the extreme forward edge of the topmostsheet and then, as the axle moves back, this sheet is rolled over andfed, printed side up, between the co-acting surfaces of the upper andlower conveyor bands 8 and 10 first on to the supports 4, 5 and thenonwards through the machine.

Associated with the supports 4, 5 there is a powderapplying arrangementthe details of which are clearly shown by Figs. 3, 4 and 5. Thisarrangement includes as a part of the aforesaid horizontal support 4, ahorizontal grid 4a with an upwardly inclined portion 5a; it alsoincludes a grid 5b virtually forming a part of the inclined support 5.However, it is to be observed that there is a gap 21 between the parts5a and 5b for a purpose to be mentioned later. Reference 22 denotes apowder container below the grid 4a. A spider 23 fixed on a shaft 24journalled in bearings in one of the side cheeks 2 and in anintermediate cheek 25, has attached to each of its limbs a powderpick-up arm 26 of irregular polygonal cross-section having amultiplicity of pick-up faces for the purpose previously indicated. Eacharm is screw-threaded at one end which is inserted through a hole in thepertaining limb of the spider and held therein by a nut 27. The arms 26project horizontally across the grid 4a. The spider shaft 24 is drivenfrom the previously mentioned shaft 19 through a toothed wheel 28 onthis shaft (see Fig. l) and a toothed wheel 29 on said spider shaft. Asthe spider 23 is rotated (anticlockwise in Figs. 2 and 4) each arm 26passes downwards beyond the forward end of the grid 4a, enters thepowder Within the container 22, picks up a quantity of powder on one ofits faces, and then passes upwards throughthe gap 21 and above a printedsheet advancing alongv the support 4 and grid 4a. As the disc continuesto rotate the face of this arm 26 whereon rests a quantity of powderassumes such a forwardly inclined position that said powder is depositedautomatically, by gravity on to the sheet. Then, as the sheet advancesup the inclined support 5, 5b, the deposited powder is spread 3 evenlyover the freshly printed matter to which it adheres. Any surplusdeposited powder falls through the grids back into the powder container22 for re-use.

From the inclined support 5,, 5b each powder-treated sheetis conveyedalong the bed 6 Where it is heated to dry the printed matter and curethe adhering powder as required to attain the effect of relief printing.As ap-' pears clearly from Fig. 6, the support 6 has perforations inalignment with suction openings 31 in the top. wall of a suction box 32below the bed. Electric heating elements 33 (see also Fig. 1) are housedbetween the bed 6 and the box 32-. In the use of the machine theseelements are connected to a suitable source of electricity, and suctionis applied to the openings 31 and perforations 30. It follows that aseach sheet advances over the heated bed 6; it is caused to make intimatecontact with the surface of the heated bed by suction effective toremove air from between the sheet and the bedfor the purpose alreadymentioned.

In Figs. 1' and 2 we have also shown infra-red lamps 34 for applyingheat to the uppersurface of each sheet as it travels along the heatedbed 6. Conveniently these lamps depend from a tubular bracket 35'.

Each sheet passes from the heateclbed 6 to: the bed 7 which may be inthe form of a box through which a cooling. medium is circulated.Moreover the-bed 7 may have through suction passages connected with' anex hauster or suction fan: In passing over the bed- 7 thesheet is cooledand so passes to therear or delivery end of the machine in non=cock1ed,fiat condition.

Take-on mechanism forming no part of the present invention is'providedat the delivery end' of the machine.

It will be understood that the timing ofthe spider 23 and the travel ofthe printed sheets is so co-related that each arm 26 deposits its powdernear the leading edge of an advancing sheet. By turning the arms 26about the axes oftheir screw-threaded ends any of the faces of the arms,which faces are of different total areas due to the irregular polygonalcross-sectionof each arm, can be made to act as the powder pick-up andcarrier fall; In short the amount of= powder deposited by eacharm isadjustable by varying the setting of the arm relatively to the spider.

Although I have described and illustrated one embodiment of theinventionit will now' be apparent'that many constructional variationsmay bemade-within the' scope of the invention as defined by the claimsthat follow;-

I claim:

1. A machine for applying powders to'freshly printed sheets,-comprising, combination, conveyor means including a grid affording aninclined path of travel for the sheetsone following another, a powdercontainer below said grid,-=a member mounted at one sided said grid forrotation in' a substantially vertical plane, powder pi'ck up arms havingamultiplicity of pick-upfaces ther'eorhsaidarms projecting laterallyfromand' rotatable'with said member in a path circumscribing said grid,thefaces of said arms dipping into said container, and mechanismforoperating said conveyor means and for rotating said member in timedrelationship whereby the faces of said arms pick up predeterminedd'os'esofpowder from said container and deposit same successively onedose over each-sheet travelling along-said grid, any unused powder fromeach dose returning through said grid into saidfcontainer;

24-A machine as set forth in claim l, each of said pick-uparms being ofirregular cross section wherebysaid plurality of 5 fac'eshave' differenttotal areas; and means securing each of" said arms to 1 said rotatablemember for turning movement relative thereto' selectively 'to'make-any'ofsaid'faces'th e' powder pick-up.

- 3. A'ma'ciiin'e'for applying powders to freshly-printedslieets-;-comprising,-in combination, conveyor means-includin'g' a gridaffording arr inclined path" or t avel or the sheets one followinganother and in line with said grid a perforated bed, a powder containerbelow said grid, a member mounted at one side of said grid for rotationin a substantially vertical plane, powder pickup arms projectinglaterally from and rotatable with said member in a path circumscribingsaid grid, said arms having a multiplicity of pick-up faces adapted todip into said container, mechanism for operating said conveyor means andfor rotating said member in timed relationship whereby said arms pick uppredetermined doses of powder from said container and deposit samesuccessively one dose over each sheet travelling along said grid, anyunused powder from each dose returning through said grid into saidcontainer, means for heating said perforated bed to dry thepowder-treated sheets travelling thereon, and suction means holding saidsheets in intimate air excluding contact with said bed.

4. A- machine as set forth in claim 3, each of said powder pick-up armsbeing of irregular cross section whereby said plurality of faces havedifferent total areas; and means securing each of said to said rotatablemember for turning movement relative thereto selectively to make any ofsaid faces the powder pick-up.

5. A mchine for automatically applying powders to freshly printedsheets,- comprising, in combination, a support for a pile of freshlyprinted sheets, sheet transfer mechanism of the suction type forsuccessively transferring the sheets from the pile support into themachine, conveyor means including a grid afiording an inclined path oftravel for' the transferred sheets, a powder container below said grid,a member mounted at one side of said grid for rotation in asubstantially vertical plane, powder pick-up arms projecting laterallyfrom and rotatable with said member in a path circumscribing said gridhaving a multiplicity of pick-up faces adapted to dip into saidcontainer, and means for operating said sheet transfer mechanism andsaid conveyor means and for rotating said member in timed relationshipwhereby said faces of said arms pick up predetermined doses of powderfrom said container and' deposit same successively one dose over eachsheet travelling along said grid, any unused powder from each dosereturning through said grid to d. e ner- 6. A machine as set forth inclaim 5, wherein each of said powderpick-up arms is of irregular crosssection whereby said plurality of faces have different total areas; andmeans securing each of said arms to said rotatable member for turningmovement relative thereto selectively to'makeany ofsaid faces the powderpick-up;

7. A machine for automatically applying powders to freshly printedsheets, comprising: in combination, a supper-t ier a' ileoffreshly'printedshee't's, sheet transfer mechanism of the"siiction'type" for successively transfer ring the sheets fr'o'in'tliepile support intothe' machine, conveyor; means including a' gi'idaffording" an inclined path of tr'avel'f or the transferred sheets andin lin'e with saidgr'ida per'forated'b'ed a'p'owder container below saidgrid, a-nieinber mounted at one side of said grid for rotation in asubstantially vertical plane, powde'r pick-up arm's praj enag' laterallyfrom" and rotatable" with said member i'n' a path circumscribing s'ai dgrid, said arms havinga multiplicity of pick-up faces adapted to dipinto said container, means for operating said sheet trans fer mechanismand said conveyor means and for rotating said m'emberin timedrelationship whereby'the faces of said'arms pick up predetermined dosesof powder from' saidcontainer and deposit same successively one doseover each sheet travelling along: said grid, anyunusedpowder'fiom"eaclrdosereturning through said grid to saidcontainer,means for heatingsaid perforated bed to'dry' the-powdentreated sheetstravelling thereon, and suction means-holding said'sheetsin intimate airexcluding contact-with said bed.

8. A machine as set forth in claim 7, each of said powder pick-up armsbeing of irregular cross section whereby the plurality of faces havedifferent total areas; and means securing each of said arms to saidrotatable member for turning movement relative thereto selectively 5 tomake any of said faces the powder pick-up.

6 References Cited in the file of this patent UNITED STATES PATENTS1,580,671 Nichols Apr. 13, 1926 1,757,528 Inman May 6, 1930 2,751,313Speed et al June 19, 1956

